Demand-limiting device



- May 29, 1923. 1,456,766

J. P. FISHER DEMAND LIMITING DEVICE Filed Aug- 29, 1919 nue nfoz A @934 a OZ" H I -Jmns P. FISHER. or-- BABTLESVI LLE; a onia,yass eaog, Be asal: s am Patented May 29, 1923.-

MENTS MHEBTYZRESEARCH C NWDEE WYQ N ei oaromruoaff Application filcaaug s t zaiem. "Serial No. weasel I T 0 all whom-it may bon c'ern: V

Belit known'that 1, JAMES P. FrsHEn, re siding at Bartlesville, in the county Jot lVashingtori, State of Oklahomayhavefl n vented-certain new? and usefulnlmprovements in- Demand-Limiting Devices; and" I do hereby declare the following to be a full,

the same. 1 V T1118 invention relates-to a demand ply line in any 'givenun it of time.

In the distribution of fluids such as natu ral or artificial in which the consump tion-is sub ect to seasonal and hourly variations, the demand may at times 1 exceed the available supply it no limit is placed on the customers consumptioni During p e rlods' of excessive demand, thoseconsrimers situated nearest the source of supply and therefore drawing their gas from sections of the m ains having the highest pressure; are able to obtaln more'than their proper ti'onate share of the available supply,-- with the result that consumersless fortunately situated may not be able to obtain an amount e fas equal to their" normal needs.

In order to obtain an equitable distribution and equality of service to all consumers,- it

is therefore. necessary to limit the amount 7 of-gaswhicli'may 5 be used by eachac on su'iner, regardless of the pressure ln'the. mains, to a definite 7 maxlmum proportioned to each consumers normalgas consumption.

By limiting the maximum 1 demand of each consumer; which limit inay' be fixed by" a service charge, the gas supply company Will-- be able at all times to supplygastoeach consumer up to-the limitfofdemand. In;

this Way, it "Will-"alsobe possible to obtaina -more un form pressure in all sections of the supply mains." lnilimiting 'the-q supa ply to eachconsumer, it-Wilh of course,- be necessary to prevent the possibility "of 5 the demand limit being changed by the" consumer and to avoid any interference with or irregularity in the' 'normal supply of gas. The object of the present invention is to provide ademand limiting device 'ofsi'mple and compact construction for limiting the -fiuid regardless oi .the

rate of passage of supply pressure.

, U.N' lTfE l EMW -L MHIWDa da" li-miting' device for limiting the quantity of fluid which may be Withdrawn from a'fiuid supdevice described in the following specificas tion and defined iii the-claims. I

5761 The variousfeatures ofthe-inventionare" l shown in the accompanying draWing; in, Y Y

sumer is enabled to obtain only the 'amount ofgascontracted for by him; 1th these and other objects fin". viewlj.

pAnoth'ei object of the invention; is topro v 1 v1de--ademand limiting "'Idevi'cejoffisimple 1'. construc't -ion-'which may be easily mountedf U i i in any of the commonly used-gas iservice pipinglsystems.

I An'otherobjeet ofthe invention-is wpr'o I vide a demand limiting device lII-WlllCll the llmitc-a-n not be-changed'with'oi'it changing v j:

parts of the apparatus, whereby each: eon;

the invention-consists in .itlieyflui'd limiting which, I

I Figure lis a 7erticalsectionalelevation I 751": a limiting device embodying a preferredforrn'"- tof theinvent on; H g;-2 lsahorizontal section ofthe de taken on line 1+l of Fig. 2,=of a demand mandlimiting'devicesonfi 2 2 f;Fig i Fig; 3*isa horizontal"'sectionl of the' def- 'man'd limiting deviceo'n-line 3-3 ofzFig.

andf '1 a Fig. 4 is edema 'vievv ofaway are:

ing part oifithedemand-limiting device,

In the V demand limiting device, of the "pres-= ent invention? -a-uniform quantity fQf fga SilS admitted. to thefservice'line through aval vef controlled by a standardorifice disk: The

gas'is p'assed through the-standard -orifice t disk under" 'adifference in pressure which:

d'ifie'rentialvisprevented from risingwa'bove" a "definite maxiiniun; #The quantit-y of gas} I I I I flowing through an orifice will'idepend"upon the-size, of 'the' orifice-andjthedifference in? pressure of the gas on oppositesides of the} orlfice disk. The 1 ,size and number K of the I orifices for any given demand 'willbe fixed!" and Will be*proportioned to the maximum; Y

quantity of gasfto be "supplied." The valved i I Whichiis controlled bythe' disk is solar. ranged that when the difference in pressure on opposite sides of the disk i corresponds with thenormal passage of-"gas, the weight of the yalve and 'disk will hold the valve in wideopen positioni" Asthe fioW'of gas and l consequentlythe'diflerence in-pressure-on I opposite sides or the disk lincreases to the T 5 demand limit,the valve'is raised by the'disfk I 1' into a partially closed position 'tozthr ottle thezga's passingto' the orifices"andqtherebyg '1 hold the pressure differential through the orifices within the fixed limit. 7

In the embodiment of the invention shown in the accompanying drawing, gas from the service main, after passing through a meter, enters the bottom of anL-shaped coupling 10 of the demand limiting device through a union nipple 12. The gas passing through the nipple 12 enters achamber 14 formed in the lower part of the .casing 10 by a flange 16 projectin'ginwardly from a valve casing 18 and acircular plate 20 rigidly supported above the flange 16 by spiders 22 extending to the walls of the valve casing 18. The flange 16 is formed with an opening 24, and a cylindrical valve cage is formed in the-casing l8 bythe wall of the opening 24 and a downwardly extending cylindrical flange 28 on the plate 20. A port 26 is provided in the valve cage between the cylindrical opening 24 and the lower edge of the flange 28. The opening 24L and the inner surface of the flange 28 are on the same cylindrical surface and a cylindrical valve 30 works in this cylindrical cage across the port 26. After the gas passes through the port 26, it flows upwardly within the walls of the valve casing 18 to an orifice disk 32 which extends across the path of the gas and loosely contacts with the walls of the valve casing 18. The orifice dislr'does not form a tight contact "\vith'the valve casing 18 but leaves a smallyspace between the edge of the disk and the wall of the casing through which a small part of the gas'leaks upwardly. The greater part of the gas, however, passes undera difference in pressure through orifices 34, Fig. 2, 111 the orifice disk 32-to theupper part, of the .casinglO from which it flows-into the domestic piping line thtough an-outlet 36. The difference ,or drop in pressure on oppo site sides of the disk 32 created by the passage of gas through theorifices Mte'nds to lift the disk upwardly through the .valve casing 18. The disk 32 is normallyprevented from rising, by the weight of, the valve 30 to which it is connected by a spindle '38 passing looselythrough the plate 20 and rigidly fastened at its ends to the disk'32 and a the valve 30. When the rate of flow of gas through the coupling 10 is below the demand limit, the weight of the .valve 80 and orifice disk 32will overcome the lifting effect of the gas passing upwardly through the orifices 24, and the orifice disk will sink to its lowest position and rest on the boss 40 up-v standing from the plate 20. i In as much as the disk 32 makes only point contacts with the boss 40, there is no tendency for it to adhere to the plate 20, iftar'or oil collects in the casing, Asthe rate of flow tends to become slightly greater than the demand limit, the lifting effect of the flowing gas will overbalancethe weight of the disk 32 and valve 30 and raise the-valve 30 to close the port 26 leading from the chamber 14. The action of the valve thus throttles the passage of gas through the port 26 and bringsthe rate of flow back to the limiting value. I

Inasmuch as the orifice, disk 32 isfdis posed across the path of flow of the gas through the device, it is subjected to a force arising from the impact of the gas on the disk as well as to the force resulting from the difference in pressure on opposite-V sides of the disk. Moreover, when the flow of gas through the device and the pressure differential across the disk are increased, the velocity ot the gas and the force of the im-. pact of the as on the disk are also increased. Vhen the fTow of the gas exceeds a certain limit, the force due to the velocity of'the gas becomes so great in proportion to the force'of the difierential across the disk that the operation of the device is rendered inaccurate. Consequently, the kinetic energy of the gas imposes a limit on the capacity of a demand limiting device in which the valve controlling element is located in the path of flow of the gas. a I

. It is found that when afluid flowing un-. derconfinement is deflected sharply in its course, as, for example, by passing through an abrupt right-angle elbow, a considerable decrease in pressure takes place. In the illustrated construction, the arrangement of the plate 20 and itsfiange 28 with relation. to the valve 30, valve casing 18, and orifice disk 32 is such that the gas after passing through the port 26 under the control of the valve '30 iscompelled to turn at right angles before passingon to the orifice disk 32. Consequently, the pressure of the is considerably reduced in passing through the valve casing 18, thus, reducing the velocity with-which thegas impinges on the orifice disk .In this'manner the plate 20 and flange 28 ac-t'to' reduce the force of the impact of the gas on the orifice disk and thereby increase the capacity of the device. 7

, In order not to interfere with the pressure at which the gas is supplied to the consumer, the orifices 34: should be of such a size that the difference inpressure on opposite sides lyoperatethe valve 30tthe orifice disk 32 is fitted to move Without friction over the walls of the valve casing 18, which it is guided. In order, to obtain a freely movable frictionless Contact between the edge of'the orifice disk 32' and the cylindrical walls of the valve casing18, the outer edge of the orifice disk is curved downwardly and bent inwardly to present a curved surface to the casing 18. '.-By thisfmeans; 'awcomparativelyfi close I contact of' considerable breadth is' formed between the edge of the disk-32and valve casing 18, whilev at tlieisame time any wedgingaction due to :a slight tilting ofthe disk 32 is prevented by the'rounded edge:

' formed on the flangeAtQ.

" fices 34 and the combined weight of thevalve 30disk '82 andspindle 38. When-the 'Fri'ction between the valve: 30 and the' edge ofthe opening 24 in the flange. 16"is also prevented by making the valve 30' a? little smaller thanthe opening 2 1 togive. considerable clearancebetweenthe valve and the edge of the opening. Aleakage' through this clearanceis of-no great;disadvantagev since a certain passage for-gas should always. be left between the chamber 14 andthe-interior of the valve casing. 18'.:, However,

when a. valve having astraight upper edge is used, there is a tendency, for the valve 'to 1 become unbalanced due to the'high velocity of the gas across itszupper edge. To avoid thisand the consequent dangerfofwedgingy the valve, a-number of notchesee are cut in the upper edgeof the. valve 30 through] which the gas may escape in a regular man neras the upper'-' edge of the valve 30, moves into the rim 28 of the valVe p'late'QOQ The notches 44 consist of anzuprightabutment face 46, an inclined face 48 extending from the'valve edge to the bottomiof the face l'fi and an inclined face '50 extending from the valve edge to the top of'the face 46. By

usingan annular valve, the pressure of the gas on one side" of the" valve is just balanced by the pressure onithe other side. With this:

construction, the valve. will not be held in closed position by the gas pressure aswould be the case if an'unbalanced valve were used;-

The quantity of? gaswwhich may pass through the demand limiting device will .depend upon the size and number o-ftheoridevice is once'installed, therefore, the demand limit cannot be changed or adjusted without changing the disk 32. To permit this adjustment to be made, the coupling 10 is providedwith aunion, nut 52 in itsxlower part in which the nipple .12 is threaded and through which access may behad to the: in

terior .ofthe device- The valve'casing 18is, supported in thecouplingilOby means .ofan

outwardly extending flange 5 lclampedsbea tween the upper edgezof the-nut.52';and-a ledge 56 formed on thecoupling 10. 'Gasketsi 58 are'provided on each side of'theflange '54 to insure a gas-tight joint. On removing.

the hut 52,'the valvel casing 18 may be removed from the coupling 10 and access had" to all parts of the apparatus.

In some cases where the demand limit is low or when the gas pressure is high the distance between the periphery of the disk 32 and the inner wall of the casing18 may be calibrated to permit all of the gas to pass aroundthe periphery Ofthe disk. Withjthis construction no orifices 34 willqb'e placed-in,

thedisk With-the: demeanin a ate the form of an elbow coupling; the device may.

service. line-quicklywithout other alteration The preferred form of .the invention havingbeen'thus. described what is claimed as V 1. In a fluid demandlimiting.devicepthe':

combination ofza valve icasingga. valve-in the said casing; a. disk connected ';to said valve and mounted .to :be. freely' mov'able along. the

innerwall of the casing-so .as to permit a limited flow of fiuidbetween the edge ofthe diskand the casing-wall, and meansfor-clee; .icreasing athe pressure of. fluid passing through" the "caslngq betweenp the valve and:

the diskt I 2. In a;fluiddemandlimiting-.device,fthe' I comb nation of: a" valvei'cas ng, an annular,v valve n sa1d cas-1ng,'an annular member nor-;.

mally spaced from tliel-upper'zedge=ofthe valveynotchgsf e lthe upperedge'of the" v valve, and: a; d sk mounted in:'said;.-casling and operable "to move the valve towardv and;

froin the. annular member...

. 3: In a. fluid demand limitingvalve in said. casing, notches. on the fu'pper edge-of said valvef'a member shaped corre- I 'deviee, the. comblnat on of-a:"valve*- casing, a hollow spondin'gly to the valve and normallyspased I from the upper-* edge of the valve, and an i orifice (1181! slidably: mounted inthe casing and operable to movethe valve towarchandj from. said member. 1

' 4.111 a -fiuid clemand-.1iniiting-.device,- the combination of avalvecasing, a disk slidably mounted 1n sa1d cas ng, a hollow ,valve. mounted. in the 'casing -and provided with notchesjon its upper edge," saidi notches comprising anupr ght. abutment' face and'in- I the valve, andconnections betweenl.-the disk cl-ined faces uat veach side-0f saidv upright 1 face,.:a member mounted 111 thecasing above and t the valve for moving the-valve forward andfromsaidmember;

' I 5, ,A fluid. demand limiting devic prising, avalve casing having :a substantiallyverticalcylindrical wall and a horizontal flange gprojecting:,inwardly- -from the wall,

a valve slid-ably contactingwith then-inner edge of said flange, a spindle connected with the valve, an orifice disk rigidly fastened to the'upper edge of the'spindle'andmounted to slide in'the valve casing, and'a platey interposed'between the valve and'the orificev disk andlconstructed and arranged to cause the fluid current to be sharply deflected in passing from the valve to the orifice disk so as to decrease the pressure of the fluid during its passage from the valve to the disk.

6. A fluid-demand limiting device comprising a valve casing, a hollow valve movable in a direction substantially parallel to the walls of the casing, an orifice'disk movable in the valve casing, a spindle for con necting-the orlflce disk to the valve, and a plate 'co-acting with the valve between thevalve and the orifice :disk and constructed to cause the fluid current to be deflected at substantially right angles in passing from the valve t the disk so as to decrease its passage lindrical chamber closed at one end, a port in the cylindrical wall of said chamber for the passage of fluid to said disk, and a freely movable slide valve actuated by said disk to move over said port. a

9. In a fluid demand limiting device, the combination of afreely movable disk, a cylindrical chamber closed atone end, a port in the cylindrical wall of said chamber for the passage of fluid to said disk, and a freely movable annular slide valve actuated by said disk to move over said port.

10. In a. fluid demand limiting device, the combination of a freely movable' disk, a cylindrical chamber closed at one end, a port in the cylindrical wall of said chamber for the passage of fluid to said disk, and a freely movable balanced slide valve actuated by said disk to moveover said port.

11. In a fluid demand limiting device, the combination of a freely movable orifice disk, a cylindrical chamber closed at one end, a port in its cylindrical wall for the passage of fluid to said disk, an annular slide valve movable over said port, vand means for rigidly connecting said valve and said disk,

12. A demand limiting device, comprising a valve casing having an inwardly extending flange, a valve plate spaced a short distance above said flange, a valve movably mounted in an opening in saidflange and arranged for closing the space between saidTflange and said valve plate, aspmdle extending from said valve through said valve plate, and an orifice diskrigidly attached to said spindle and slidably contacting with the walls of said casing. ,4 i

13. A'demand limiting device, comprising a valve casing, a valve cage mounted'in said casing having a substantially vertical cylindrical wall, a valve plate arranged toclose the upper end of said cage, ports in said cage, an annular valve arranged to move across said ports, notches in the upper edge of said valve, a spindle connected to. said valve and extending through said valve plate, and a movable orifice disk rigidly fas-' tened to the upper end of said spindle and slidably contacting with the walls of said valve casing.

14.111 a fluid demand limiting device, the combination of a valve casing, a valve cage in the casing comprising a cylindrical member closed atits upperv end and having its periphery spaced from the wall of the cas- I 111g, an orifice disk above the cylindrical member, a valve mounted for movement in the valve cageand adapted to be'received in thecylindrical member, and connections betweenthe orifice disk and the valve for moving the valve toward and from the cylindrical member, the arrangement of the valve, the cylindrical member, the valve casing, and the orifice disk being such that the fluid current is deflected substantially at right angles during its passage from the valve to the orifice disk so as to decrease the pressure of the fluid during its passage from the valve to the disk.

15. A demand limiting device comprising, an L-shaped coupling threaded at its open: ings, a". valve casing secured within one opening of said coupling bymeans of a union nut, a valve cage in the casing, a union nipple mounted in said nut, aport in said cage, a valve in said cage arranged to open and close said port, and a disk connected with said valve and slidably' mounted in the valve casing; I

16. A fluid demand limiting device comprising a valve casing, a valve slidably mountedin the casing, an orifice disk connected 'to'the valve, and a member co-acting with the valve to control the passage of fluid through the casing and constructed and arranged with relation to said first mentioned parts so as to decrease the pressure of the fluid during its passage from the valve to'theorifice disk.

In testimony whereof I aflix my signature.

JAMES P. FISHER; 

